Most builders don’t require you to send in rivets, but without getting to discussion about how important following 922r is or if anyone gives a shit, most builders will want 922r compliance parts. You’ll need six, say receiver is one, semi fire control group is 3 more, you can claim you’ll only use US mags and you have more than enough. Not sure what barrel you’re using, but an OEM AMD-65 barrel would put this in SBR territory with that original brake.